1. Field of the Invention
This invention relates to a substrate transport apparatus and, more particularly, to a substrate transport apparatus with an articulated arm supporting a substrate holding support.
2. Prior Art
Various types of substrate transport apparatus with articulated arms are described in the following art:
U.S. Pat. No.: 5,151,008
U.S. Pat. No.: 5,180,276
U.S. Pat. No.: 5,404,894
U.S. Pat. No.: 5,577,879
U.S. Pat. No.: 5,647,724
PCT Publication No.: WO 94/23911
PCT Publication No.: WO 97/26117
In accordance with one embodiment of the present invention, a substrate transport apparatus is provided. The substrate transport apparatus comprises a drive section and an articulated arm assembly. The articulated arm assembly is pivotably mounted to the drive section. The arm assembly has a first end connected to the drive section and the second end opposite the first end supporting an end effector thereon. The articulated arm comprises a pair of opposing forearms on opposite sides of an axis of translation of the end effector. The axis of translation extends substantially over the center of the first end of the drive assembly. When the arm assembly is retracted to a home position, the second end of the arm assembly is over the center of the first end of the arm assembly, and the opposing forearms are angled relative to the axis of translation at an angle of about 90xc2x0.
In accordance with another embodiment of the present invention, a substrate transport apparatus is provided comprising a drive section and a movable arm assembly. The movable arm assembly comprises two proximal arm members and two end effectors. Each proximal arm member is connected to the drive section so that the two proximal arm members are generally crossed. The end effectors are located at opposite ends of the proximal arm members, with each end effector being connected to an end of each proximal arm member. When the end effectors are over the drive section, the proximal arm members are vertically aligned.
In accordance with still another embodiment of the present invention a substrate transport apparatus is provided. The substrate transport apparatus comprises a frame, an articulated arm having a pair of opposing upper arms and a pair of forearms, means for synchronously rotating one of the forearms and a pair of counter rotating elements. In addition to the upper arms and forearms the articulated arm has an end effector. The upper arms are pivotably connected to the frame at a shoulder joint of the articulated arm. A first one of the forearms is pivotably connected to a first one of the upper arms at a first elbow joint of the articulated arm. A second one of the forearms is pivotably connected to a second one of the upper arms at a second elbow joint. The forearms are pivotably connected to the end effector at a wrist joint of the articulated arm. The means for rotating a forearm synchronously rotate an elbow end of the second forearm with the rotation of the first upper arm. The means for synchronously rotating the second forearm comprise at least one rotation transfer element extending between a shoulder end of the first upper arm and an elbow end of the second forearm so that rotation of the first upper arm directly rotates the elbow end of the second forearm. The pair of counter rotating elements are supported by the forearms. The counter rotating elements counter rotate relative to each other about a common axis of rotation at the wrist joint. The counter rotating elements restrainingly contact the end effector to guide the end effector true to an axis of translation of the end effector.